Nylander got to a loose puck during a scramble in front of the net after a shot from Kyle Clifford and made it 4-3 with 11:00 remaining.
"I think we got them, they had the far change there in the second period, and we were able to, once they got it out, just go right back in the [offensive] zone and spend some heavy shifts in the O zone, which was good," Nylander said. "I think our [defensemen] have been playing great, but obviously it's great to spend time in the O zone. I think that's where we kept their best players out of our D zone, which helped us a lot."
Kasperi Kapanen got Toronto within 3-2 with 2:17 left in the second period when he took a pass from Jason Spezza and shot from the left face-off dot, and Matthews tied it 3-3 1:15 later.
"It was one of those games where we didn't do the right things around the offensive zone or manage the puck well," Florida coach Joel Quenneville said. "I thought they were better in the neutral zone than we were tonight. It was a disappointing game. I thought Sergei was all right, he made some big saves in the second and third and gave us a chance, but we have to find a way at home to get something out of this game."
The Panthers took a 1-0 lead at 2:23 of the first period when Mark Pysyk one-timed a pass from Aaron Ekblad at the bottom of the right face-off circle. Zach Hyman tied it 1-1 at 3:32 when he backhanded a rebound from Matthews' shot at the top of the goal crease. Mike Hoffman scored at 7:25 to put Florida up 2-1 off a rebound from Frank Vatrano's shot on a 2-on-1. Noel Acciari made it 3-1 at 12:36 with a shot from the right-wing boards.
Justin Holl scored into an empty net with 21 seconds left for the 5-3 final.